Search

In this study, the purification and characterization of a novel polysaccharide-based bioflocculant BM2 produced by a bacterium Bacillus megaterium strain PL8 with self-flocculating property were investigated. The results showed that BM2 was an acidic polysaccharide composed of Gal, GalUA, Glc, GlcUA and Man at a molar ratio of 45.1: 33.8:9.3:9.2:2.4, respectively. The molecular weight of BM2 was 4.55 × 106 Da. BM2 had high flocculation efficiencies across a wide pH ranged from 4 to 11 and a wide temperature ranged from 20 to 100 °C towards kaolin clay. BM2 was a cation-independent bioflocculant which could achieve high flocculation activity without the addition of other cations. Adsorption bridging was the main mechanism in the flocculation process of BM2 towards kaolin clay. The BM2 also displayed a high removal efficiency in terms of Congo red (88.14%) and Pb2+ ions (82.64%). These results suggested that BM2 had a great potential as an efficient bioflocculant candidate in wastewater treatment.

Human milk fat substitutes (HMFSs) are the structured lipids intended for infant formula. It provides energy and essential fatty acid for infant. HMFSs are mainly prepared by enzymatic method. In this study, we aim to explore the potential for producing HMFSs by fermentation using R. opacus. The results indicated that different compounds with chain length from 12 to 18, used as carbon source, could be incorporated into triacylglycerols directly. Polyunsaturated fatty acids in term of ARA, EPA, DHA could enter the kennedy pathway directly and involved in the biosynthesis of triacylglycerols. GC, UPLC-MS and 13C-NMR analysis demonstrated that typical structured lipids β-OPL (40.09%) was synthesized in R. opacus. Transcriptome analysis revealed that β-oxidation, fatty acid elongation and kennedy pathways existed in R. opacus. It was concluded that fatty acid supplied as carbon source could enter the kennedy pathways directly or via the de novo fatty acid biosynthesis pathway depending on the chain length, thus, affect the triacylglycerol species formed in the Rhodococcus opacus.

Human milk fat substitute (HMFS) is a class of structured lipids widely used in infant formulas. Herein, HMFS was prepared by Rhodococcus opacus fermentation. The substrate oils suitable for HMFS production were coconut oil (66.1-57.5%), soybean oil (17.5-26.5%), high oleic acid sunflower oil (5.4-4.5%), Antarctic krill oil (9-9.5%), and fungal oil (2%). Six HMFSs were prepared, among which HMFS V and VI were similar to human milk fat from Chinese in terms of fatty acid composition and triacylglycerol species. The sn-2 position of HMFS was occupied by palmitic acid (49.31 and 43.48% in HMFS V and VI, respectively). The major triacylglycerols were OPL, OPO, and LPL, accounting for 15.90, 9.49, and 6.84 and 17.52, 8.44, and 8.55% in HMFS V and VI, respectively. This study is the first to prepare structured lipids intended for infant formula through fermentation, providing a novel strategy for the edible oil industry.

Professor总结杨继国教授治疗功能性胃肠病的临床经验。杨继国教授认为本病多因六腑虚弱所致，六腑通降失调是其基本病机，以补益肠胃、通降六腑、疏肝安神为选穴原则，运用针刺与脐灸联合治疗。针刺以捻转震颤催气手法为主，脐灸针对六腑虚弱，补脾益胃，调和六腑，标本兼治。.

Objective Objective:To observe the therapeutic effect of cross-shaped moxibustion on the conception vessel and belt vessel for dysmenorrhea due to qi and blood deficiency. Methods Taking Shenque (神阙CV8) as the center, up to Zhōngwǎn (中脘CV12), down to Zhōngji (中极CV3), and both sides to Daimai (带脉GB26),the above mentioned were treated area. The patient's umbilicus was filled with the herbal powder for moxibustion and the powder was also scattered in a straight line along the treated area. The two sheets of mulberry paper were put in a cross way on the herbal powder for moxibustion, and the cross-shaped moxibustion box was put on the paper. The ginger paste was put into the box to a height of 3 cm and pressed tightly with a tongue depressor, the margin of the ginger paste should be clinged to the moxibustion box. The moxa cones were put end to end in the groove on the median of the ginger paste and ignited orderly. When the cones were burnt completely, the new cones were used and ignited. Three cones were adopted in succession in each treatment. The treatment was given once a week, and three treatments as one course,the therapeutic effect was evaluated after two courses of treatment. Results There were 16 cases cured,5 cases effective and 2 cases non-effective in all. The total effective rate was 91.3%. Conclusion Coss-shaped moxibustion on the conception vessel and belt vessel has sound effect for dysmenorrhea due to qi and blood deficiency.

Based on the concept of endophytic fungus, if endophytic fungus can produce the same or similar product as the host plant, which will get rid of the restrictions of farmland, seasonal and pest, the active product could be sustainably obtained. In this study, an endophytic fungus polysaccharide FP showing the similar structure with the host Dendrobium officinale polysaccharide (DOP) was sustainably and cost-effectively obtained under preferred reaction conditions with different C/N ratio. The FP with high yield up to 2.77 ± 0.51 g/L showed same monosaccharide composition with DOP as well as some host-plant-associated polysaccharides in published literatures. The main chain of FP was composed by →3,6)-β-L-Man-(1→, α-D-Glc-(1→, →4)-α-D-Glc-(1→, →3,6)-β-D-Gal-(1→, and →6)-β-D-Gal-(1→, while the side chain was α-D-Glc-(1→. Meanwhile, FP was confirmed as a safe polysaccharide with good antioxidant, antiglycation and immunomodulatory activities. Furthermore, TLR2 and TLR4 were confirmed as the membrane receptors of FP on RAW264.7 cells.

The asymmetric addition of ammonia to unsaturated acids using engineered methylaspartate ammonia lyase (MAL) is a particularly attractive and atom-economic method for the synthesis of unnatural ami...

Considerable attention has been given to the development of robust fermentation processes, but microbial contamination and phage infection remain deadly threats that need to be addressed. In this study, a robust Escherichia coli BL21(DE3) strain was successfully constructed by simultaneously introducing a nitrogen and phosphorus (N&P) system in combination with a CRISPR/Cas9 system. The N&P metabolic pathways were able to express formamidase and phosphite dehydrogenase in the host cell, thus enabled cell growth in auxotrophic 3-(N-morpholino)propanesulfonic acid medium with formamide and phosphite as nitrogen and phosphorus sources, respectively. N&P metabolic pathways also allowed efficient expression of heterologous proteins, such as green fluorescent protein (GFP) and chitinase, while contaminating bacteria or yeast species could hardly survive in this medium. The host strain was further engineered by exploiting the CRISPR/Cas9 system to enhance the resistance against phage attack. The resultant strain was able to grow in the presence of T7 phage at a concentration of up to 2 × 107 plaque-forming units/ml and produce GFP with a yield of up to 30 μg/109 colony-forming units, exhibiting significant advantages over conventional engineered E. coli. This newly engineered, robust E. coli BL21(DE3) strain therefore shows great potential for future applications in industrial fermentation.

Two polysaccharides, DGS1 and DGS2, were obtained by solid-state fermentation (SSF) of Fusarium solani DO7, an endophytic fungus isolated from the orchid Dendrobium officinale. Structural characterizations revealed that DGS1 consisted of arabinose, glucose, mannose and galactose with a molar ratio of 2.9:13.4:3.0:1, respectively, and contained (1 → 5)-Araf, (1 → 4)-Glcp, (1 → 6)-Glcp, (1 → 3)-Manp, (1 → 2,6)-Manp and (1 → 6)-Galp glycosidic linkages, while DGS2 was composed of arabinose, glucose, mannose and galactose in a molar ratio of 3.5:8.1:2.1:1, respectively, and contained (1 → 5)-Araf, (1 → 4)-Glcp, (1 → 6)-Glcp, (1 → 3)-Manp and (1 → 6)-Galp glycosidic linkages. Neither polysaccharide was toxic to human embryonic kidney cells or mouse RAW 264.7 macrophage cells. An immunomodulatory activity assay indicated that both polysaccharides could significantly enhance the levels of TNF-α, IL-6 and NO by activating TNF-α, IL-6 and iNOs gene expression, respectively, especially DGS2. Interestingly, DGS2 also possessed relatively high antioxidant activity. These results illustrate that, due to its cost-effectiveness and environmentally friendly features, SSF has significant potential as a commercially competitive source of natural products, including fungal polysaccharides, with immunomodulatory activity.

To explore the clinical efficacy and possible efficacy mechanisms of Governor Vessel moxibustion therapy in patients with carotid atherosclerosis (CAS).A total of 100 patients with CAS were randomly divided into Governor Vessel moxibustion therapy group (After the treatment, the constitution score and BMI were significantly reduced, and the IMT, TC, TG, LDL, Fbg and hs-CRP decreased significantly in the patients of the two groups as compared with those before treatment (The Governor Vessel moxibustion therapy can effectively treat CAS, and its mechanism may be related to the improvement of risk factors such as high level of TC, TG, LDL, Fbg, and hs-CRP.

Human milk fat substitute (HMFS) is a class of structured lipids widely used in infant formulas. Herein, HMFS was prepared by

Food contamination caused by microorganisms has become a threat to consumers' health. Exploring antagonistic endophytes from plants of food raw-material and applying bioactive metabolites to inhibit the contamination has been an alternative and safer solution. In this study, we isolated and screened potential antagonistic endophytes from fresh Camellia assamica leaves, which were widely used in tea beverage production. We focused on a strain that showed visible inhibitory activity to Gram-positive bacteria, Gram-negative bacteria, and fungi. It was identified as a member of Bacillus velezensis and named FZ06. The results of genome analysis showed the strain FZ06 had 167 single-copy specific genes, much higher than those of most related strains. Also, 11 potential gene clusters of antimicrobial metabolites were found. Three groups of lipopeptides (surfactin, iturin, and fengycin) were identified by UPLC-MS/MS in purified antimicrobial methanol fraction of strain FZ06. The results of minimum inhibitory concentration (MIC) test proved the lipopeptide extract showed significant inhibitory effect on food spoilage bacteria (MIC 512−2048 μg/mL) and toxigenic fungi (MIC 128−256 μg/mL). In conclusion, this study suggests that the endophytic B. velezensis FZ06 and its lipopeptide extract hold great potential applications in the inhibition of food spoilage bacteria and toxic fungi in food industry.

Odd-chain fatty acids (OCFAs) naturally occur in bacteria, higher animals, and in plants. During recent years, they have received increasing attention due to their unique pharmacological properties and usefulness for agricultural and industrial applications. Recently, OCFAs have been identified and quantified in a few organisms, and new pharmacological functions of OCFAs have been reported. Some of the publications are related to the optimization of OCFA production through fermentation and genetic engineering. The present review aims to provide a summary on the recent progress in the field of microbial-derived OCFAs. More specifically, we outline the publications of OCFAs related to (i) different sources of OCFAs; (ii) endogenous synthesis of OCFAs; (iii) production of OCFAs through fermentation; (iv) genetic engineering related to OCFA; and (v) role of OCFAs in human health and disease. Finally, some areas that require further research are discussed.

The combined treatment with umbilicus moxibustion and acupuncture achieves the significant effect on hormone-dependent high fever. The medical case was recorded so as to provide the approach to the clinical treatment or the reoccurrence control of this disease.

A 56-year-old female patient with interstitial cystitis was treated with umbilical moxibustion combined with acupuncture. The doctor prepared the wheat flour-made bowl and the herbal powder for umbilical moxibustion. The bowl was put on the patient's umbilicus with a small hole in the middle of the bowl directly facing the navel, in which, the herbal powder was filled. The moxa cone was put on the bowl and ignited. Totally, 3 cones were used. During umbilical moxibustion, acupuncture was adopted at Guānyuan (关元CV12), Zhōngji (中极CV3), Dahe (大赫KI12), etc. The above treatment was given twice a week and 2-week treatment was as one course. After 4 courses of treatment, the clinical symptoms basically disappeared. The cystoscopic examination results were recovered to be normal.

The combined treatment of cangguitanxue (green turtle probing its cave) needling technique and cupping method achieved the significant therapeutic effects on 1 case of traumatic soft tissue injury. Such therapeutic method provides the reference for the clinical treatment of soft tissue swelling due to injury.

Chitinase is a promising biocatalyst for chitin biotransformation in the field of recalcitrant biomass degradation. Excellent catalytic performance is conducive to its commercial utilization. In this work, sequence- and structure-based semi-rational design was performed to evolve the thermostability and activity of a previously identified chitinase PpChi1 from Paenibacillus pasadenensis CS0611. After combinational mutagenesis, the mutant S244C-I319C/T259P with disulfide bond introduction and proline substitution exhibited higher specific activity at higher temperature, 26.3-fold in half-life value at 50 °C, and a 7.9 °C rise in half-inactivation temperature T1/215min compared to the wild-type enzyme. The optimal reaction temperature of the mutant was shifted from 45 °C to 52.5 °C. Molecular dynamic simulation and structure analysis confirmed that these improvements of the mutant were attributed to its stabilized folding form, possibly caused by the decreased entropy of unfolding. This work gives an initial insight into the effect of conserved proline residues in thermostable chitinases and proposes a feasible approach for improving chitinase thermostability to facilitate its application in chitin hydrolysis to valuable oligosaccharides.

Background Glucaric acid, one of the aldaric acids, has been declared a “top value-added chemical from biomass”, and is especially important in the food and pharmaceutical industries. Biocatalytic production of glucaric acid from glucuronic acid is more environmentally friendly, efficient and economical than chemical synthesis. Uronate dehydrogenases (UDHs) are the key enzymes for the preparation of glucaric acid in this way, but the poor thermostability and low activity of UDH limit its industrial application. Therefore, improving the thermostability and activity of UDH, for example by semi-rational design, is a major research goal. Results In the present work, three UDHs were obtained from different Agrobacterium tumefaciens strains. The three UDHs have an approximate molecular weight of 32 kDa and all contain typically conserved UDH motifs. All three UDHs showed optimal activity within a pH range of 6.0–8.5 and at a temperature of 30 °C, but the UDH from A. tumefaciens (At) LBA4404 had a better catalytic efficiency than the other two UDHs (800 vs 600 and 530 s−1 mM−1). To further boost the catalytic performance of the UDH from AtLBA4404, site-directed mutagenesis based on semi-rational design was carried out. An A39P/H99Y/H234K triple mutant showed a 400-fold improvement in half-life at 59 °C, a 5 °C improvement in $$ {\text{T}}_{ 5 0}^{ 1 0} $$ T 50 10 value and a 2.5-fold improvement in specific activity at 30 °C compared to wild-type UDH. Conclusions In this study, we successfully obtained a triple mutant (A39P/H99Y/H234K) with simultaneously enhanced activity and thermostability, which provides a novel alternative for the industrial production of glucaric acid from glucuronic acid.

Odd-chain fatty acids (OCFAs) have been reported to possess pharmacological activity and have been used in the manufacture of agricultural and industrial chemicals. We here provided a new method to increase the OCFAs content in oil produced by Rhodococcus opacus PD630 through addition of 1-propanol to the fermentation media. The OCFAs in oil of R. opacus PD630 are primarily pentadecanoic acid (C15:0), heptadecanoic acid (C17:0) and heptadecenoic acid (C17:1). After adding 0.5–1.5% (v/v) 1-propanol, the production of oil increased from 1.27 g/L to 1.31–1.61 g/L, and the OCFAs content in oil increased by 46.7–55.1%. Metabolic intermediates determination and transcriptome analysis revealed that R. opacus assimilated 1-propanol through methylmalonyl-CoA pathway. When the nitrogen source was limited, propionyl-CoA was converted to propionyl-acyl carrier protein (ACP) which could be used as primer during the elongation of fatty acid synthesis. Then OCFAs were produced when odd number of propionyl-ACP was incorporated in the cycles of fatty acid synthesis.

In this study, the primary antibacterial ingredients in Fusarium solani DO7 were confirmed as polysaccharides. After purification, two polysaccharides, DY1 and DY2, exhibited excellent antibacterial activity, especially to S. aureus and E. coli. Moreover, the glycosidic linkages of DY1 were composed of (1 → )-α-D-Glcp, (1 → 3)-β-L-Rhaf, (1 → 4)-β-D-Xylp, (1 → 6)-α-D-Glcp, (1 → 2,6)-α-D-Glcp and (1 → 2)-β-D-Galp; while the glycosidic linkages of DY2 contained (1 → )-β-D-Glcp, (1 → 2)-α-L-Rhaf, (1 → 3)-α-L-Araf, (1 → 4)-β-D-Glcp, (1 → 4,6)-β-D-Glcp and (1 → 3)-α-D-Galp. Additionally, DY1 and DY2 possessed nontoxicity to RAW 264.7 cells. Both polysaccharides could significantly promote the levels of TNF-α, IL-6 and NO by activating TNF-α, IL-6 and iNOs mRNAs expression. These results indicated that DY1 and DY2 had great potential as a food preservative and immunomodulatory agent.

Different kinds of low transition temperature mixtures (LTTMs) were synthesized with DL-lactic acid and five different quaternary ammonium salts respectively, and their viscosity and solubility parameters change with different molar ratios of quaternary ammonium salt to DL-lactic acid were investigated and compared with anthocyanins. Then the LTTMs synthesized were used to extract anthocyanins from saskatoon berry (Amelanchier alnifolia Nutt.). It turned out that the choline chloride/DL-lactic acid (ChCl/LA) showed the best solubility of anthocyanins compared with the other LTTMs, which was in line with solubility parameter theory. Under the optimized process condition with 1 : 15 of molar ratio, 1 : 20 of solid to liquid ratio, 50 °C of extraction temperature and 45 min of extraction time, the extraction amount of anthocyanins reached 525.27 ± 0.82 mg per 100 g and the extracted rate of anthocyanins was 87.4%. Then the macroporous resin AB-8 adsorbent was used to separate and purify the anthocyanin compounds from saskatoon berry, with a recovery yield of 65.7%. Further, the confirmation of the purified anthocyanins was carried out using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and high performance liquid chromatography-mass spectrometry (HPLC-MS). Finally, the purified anthocyanins were proved to be good antioxidants through the comparison with vitamin C and butylated hydroxytoluene.

Chiral alcohols and their derivatives are vital building blocks to synthesize pharmaceutical drugs and high-valued chemicals. Wild-type carbonyl reductase AcCR from Acetobacter sp. has ideal enantioselectivity toward 11 prochiral substrates (e.e.>99%) but poor activity. In this work, a semi-rational engineering was performed to enhance the activity of AcCR. Fortunately, three positive double-mutants (mut-E144A/G152 L, mut-G152 L/Y189 N, and mut-I147 V/G152 L) with specific activity 17–61 folds higher than that of enzyme without modified were achieved. Kinetic studies suggested that the catalytic efficiencies (kcat/Km) of these mutants were also well enhanced. Finally, these modified mut-AcCRs were successfully applied in asymmetric reductions of 11 structurally diverse prochiral substrates (200 mM) with excellent product yields (76.8%–99.1%) and enantiomeric excess (e.e.>99%), which provides an alternative strategy for efficient synthesis of chiral alcohols for pharmaceuticals industry with ideal yield and enantioselectivity.

An enzymatic degumming trial of soybean oil was carried out at a capacity of 400 tons/day by applying microbial phospholipase A1 from Thermomyces lanuginosus/Fusarium oxysporum. When the pH was kept in the range of 4.8–5.1, less than 10 mg/kg of phosphorous content of The oil was obtained. The gum and oil were easily separated after centrifugation and the oil loss was minimal under the process conditions. Through analysis of phospholipids compounds in the gum by Electrospray Ionization-Mass Spectrometer and phosphorous content, it could be seen that both glycerophospholipids and lysophospholipids existed with contents of 45.7 and 54.3%, respectively. The performance of enzymatic degumming was found to be related to the production of glycerophospholipids.

An enzymatic process optimization and a largescale plant trial for rapeseed oil degumming were carried out by a novel microbial lipase. Response surface methodology was used to obtain the desired data in the process optimization. Enzyme dosage, temperature, and pH were important determining factors affecting oil degumming. The optimal set of variables was an enzyme dosage of 39.6 mg/kg, a temperature of 48.3°C, and a pH of 4.9. The phosphorus content could be reduced to 3.1 mg/kg at the optimal levels of the tested factors. An enzymatic degumming plant trial was performed on a 400 tons/d oil production line. pH was found to play an important role in degumming performance. When the pH was 4.6–5.1, the corresponding phosphorus content of degummed rapeseed oil could be reduced to less than 10 mg/kg, which met the demands of the physical refining process.

A short C—N distance [1.394 (2) Å] in the title compound, C11H10N3O4S+·NO3−, is indicative of some conjugation of the sulfonamide π electrons with those of the pyridinium ring. The crystal structure is stabilized by N—H...O hydrogen bonds.